A variety of implanted medical devices can be used to extend and improve the life of a patient. These implanted medical devices often include electronics that monitor internal and external parameters and control the application of various therapies. To prevent body fluids from damaging electronic components that may be present within the device, the circuitry included in the internal unit is often enclosed by a hermetically sealed case. An electrical feedthrough may be used to transfer signals from the circuitry inside the hermetic case to the exterior of the case and vice versa. This electrical feedthrough maintains the integrity of the hermetic case, while allowing electrical signals to pass through.
Making reliable electrical connections between the vias in the hermetic feedthrough and an external device can be challenging. In some devices, the hermetic feedthrough and vias may be miniaturized. The miniaturization may result in very small cross-section vias, wires and connections. Tensile or compressive forces may be applied to wires or vias, resulting in stresses in the wires, vias, and connections. Implantation in a dynamic biological system may lead to fatigue failure of the connections, vias, or wires. The connections may also be degraded by biological or chemical attack.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.